With Britain transitioning out of the European Union, the United Kingdom regulator obtained an exemption from the EU's medicines agency, which has stressed it prefers to wait for further review and consultations across the 27-nation bloc.
"Is it easy? No", he said, "but we're going to be fine, and the whole supply chain will work together to make sure that people across the USA are getting the vaccines they need to, and making sure the temperatures are maintained".
It reported that an unnamed person directly involved in the development of the Pfizer vaccine said "some early batches of the raw materials failed to meet the standards", which caused production delays.
As of now, Pune-based Serum Institute of India (SII) has said that it too will apply for emergency use licensure for the AstraZeneca-Oxford vaccine being manufactured by it in a couple weeks' time.
"In fact, they were even rather severely criticized by their European Union counterparts who were saying, you know, 'That was kind of a hot dog play, '" Dr Fauci had said.
"I sincerely hope that this gives the people of the United Kingdom confidence that we're ready now to deliver the vaccine to all four corners of our nation", he told journalists on Wednesday.
That vaccine, an "inactivated" shot made by growing the whole virus in a lab and then killing it, also is in use in the UAE.
Elderly people in care homes and care home staff have been placed top of the priority list - which is recommended by the Joint Committee on Vaccination and Immunisation - followed by over-80s and frontline health and care staff.
BioNTech, which owns the vaccine, said it has so far signed deals to supply 570 million doses worldwide in 2021, with options to deliver 600 million more.
Setting out the "immense logistical challenges" in getting the vaccine into care homes, Mr Johnson told the briefing: "Of course we want to get it into care homes to protect the most vulnerable as fast as we possibly can".
The vaccine has been tested on 43,500 people in six countries and no safety concerns were raised. People will be sent appointments with details of the location where they will receive the vaccination, dependent on where they are on the schedule and risk. NBC's Lester Holt asked in an interview on Thursday night, prompting a startling response from Bourla: "I think this is something that needs to be examined".
"But they just took the data from the Pfizer company and instead of scrutinizing it really, really carefully, they said, 'OK, let's approve it. Words such as the ones we've heard perhaps".